Heel-reinforcing insert



United States Patent 3,186,112 HEEL-REINFORCING lNSERT Arthur F. Ball, Haverhill, Mass., assignor to Essex Products, Inc., Haverhill, Mass., a corporation of Massachusetts Filed Feb. 18, 1963, Ser. No. 259,058 4 Claims. (Cl. 36-34) The present invention relates to heel reinforcing inserts and, more particularly, to thin stem plastic heels employing reinforcing structures that carry with them the heel lift.

In my copending applications S.N. 731,040, led April 25, 1958, for Reinforced Heel, Insert, Method, and S.N. 69,689, filed November 16, 1960 for Reinforcing Heel Insert and Heel, now Patent No. 3,106,791, granted October 15, 1963 there are disclosed novel inserts or dowels that provide structural rigidity to thin-stem plastic heels and the like, with insurance that the reinforcing dowel employed therein cannot move or slip in any direction or orientation within the same, and with the added feature of securing a toplift to the heel that cannot separate or move relative to the heel and its reinforcing dowel.

The latter application also discloses heel insert constructions that are particularly adapted for impact-stretchable plastic lift materials.

While the structures above-described have served admirably in commercial practice, there has arisen the requirement for a very high-grade type of heel-reinforcing insert and toplift-carrying insert that, particularly when employed with plastic materials of the type that tend to stretch upon impact, maintain the general original configuration of the plastic portion of the lift, and provide a continual cushioning action of the plastic material, even as the lift is worn down through usage.

It is to the solution of this particular problem that the present invention is primarily directed, it being an object of the invention to provide a new and improved heel-reinforcing insert of the vabove-described character. Still another object is to provide -a new and improved heel-reinforcing insert of more general utility, also.

Other and further objects of the invention will be explained hereinafter and will be more particularly pointed out in connection with the appended claims.

In summary, however, from one of its important aspects, the present invention contemplates a reinforcing heel insert comprising a hard metal dowel and the like, a frusta-conical cup provided with a cover rigidly secured to the lower end of the dowel, prong means rigidly secured to the cup within the same, and a frusto-conical lift member, preferably of resilient plastic, conforming to the shape of the inner walls of the cup and secured therewithin and to the prong means, the slant height of the lift member being greater than that of the cup in order to provide a frusto-conical projection of the lift member below the cup. Preferred constructional details are hereinafter presented.

The invention will now be described in connection with accompanying drawings, FIG. l of which is an isometric view illustrating the insert of the present invention; and

FIG. 2 is a longitudinal sectional view of the lower portion of the insert, constructed in accordance with a preferred embodiment of the invention and upon an enlarged scale.

Referring to FIG. 1, a reinforcing dowel insert of the general type described in the said copending application is illustrated at 11, as of hardened steel and the like, intermed-iately provided with ridge means 15 for driving into the walls of a recess 9 in the thin stem 5 of a plastic or similar heel 1. The recess 9 extends from the lift end 7 of the heel tread, up preferably almost to the heel seat 3. The ridge means 15 is shown in the preferred form of a plurality of blades, though continuous ridge means or other securing means may be employed; but in some cases, the ridge means 15 will extend to points representing a slightly greater diameter than the body of the dowel 11 and of slightly greater diameter than the inner diameter of the recess 9 in the heel stem 5', in order that the driving of the insert 11 into the recess 9 will secure the dowel against all possible longitudinal, circular or other movement therein.

The longitudinally extending dowel 11 is provided at its lower end with a head structure 17 which is of diameter much larger than that of the ridges 15 and that is connected to a truste-conical cup 2, preferably of metal, such as steel. The frusto-conical cup 2 is shown provided vvith a top cover 4 containing a centrally disposed aperture 6 within which the head 17 may be secured by a swedging or other well-known riveting technique, as shown in FIG. 2. The head 17 becomes thus locked to the cover 4, with the lower portion thereof preferably being slit or segmented and expanded to form outwardly and downwardly extending prongs or projections 17', with a depressed central region 4 of the cover 4 locked between the upper portion of the head 17, that serves as a locking collar, and the prongs 17' within the cup 2. In the swedging or riveting process, small locking indentations 8 may be formed to provide a unitary secured structure 11-2.

Within the frusto-conical `cup 2, preferably resilient plastic, such as the urethanes and other impact-stretchable plastic materials, including some forms of nylon and the like, is molded or yotherwise secured, locking to the prongs or projections 17 and providing a substantially frusto-conical plastic lift 10 conforming to the shape of the inner walls of the cup 2 and secured therewithin.

In accordance with the invention, the slant height of the plastic lift 10 is made greater than that of the cup 2 in order to provide a frusto-conical resilient plastic projection 10' of the lift 10 extending below the lower edge lof the cup 2.. The lower portion 10 of the plastic lift preferably protrudes outwardly at the bottom edge of the cup 2 to continue as an in-line extension of the outer conical surface of the cup therebelow.

The reason for this construction resides in the discovery that, even as the lift assembly structure 2-10-10' wears down in usage, a cushioning layer, such as 10 or a smaller layer thereof, will always be in position between the lower edges of the cup 2 and the ground or other surface against which the heel strikes in usage. This construction thus provides a continuous cushioning action which has been found desirable, even as the lift wears down with considerable usage.

Clearly the construction of the present invention may be fabricated in other ways as by making a unitary coldhead cup nail as a one piece product; but such modifications are considered to fall within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. A reinforcing heel insert comprising a dowel, a frusto-conical cup having a cover with an aperture therethrough, said dowel extending through said aperture and having a locking collar at the upper surface of said cover and depending prong means at the lower surface of said cover, said collar and said prong means gripping said cover therebetween to secure said dowel to said cup, and a frusto-conical lift member conforming to the shape of the inner walls of the cup, secured in said cup to the prong means, and adhered to said inner walls, the slant height of the lift member being greater than that of the cup in order to provide a frusto-conical projection of the References Cited by the Examiner lift member below the cup.

2. The insert lof claim 1, said doWel being hard metal UNITED STATES PATENTS and said lift member being resilient plastic molded into 2,932,098 4/ 60 Lange 36-34 said cup. 5 3,043,024 7/62 Haug 36-36 3. The insert of claim 1, said cover having' a depression 3,094,793 6/ 63 Reichel 36-36 receiving said collar, said prong means being a multisegmented head. JORDAN FRANKLIN, Primary Examiner.

4. The insert of claim 1, said lift member projection covering the bottom edge of the cup, with the outer walls 10 DAVID J- WILLIAMOWSKY, FRANK L COHEN,

of the projection constituting an in-line extension of the Examinersouter conical surface of the cup. 

1. A REINFORCING HEEL INSERT COMPRISING A DOWEL, A FRUSTO-CONICAL CUP HAVING A COVER WITH AN APERTURE THERETHROUGH, SAID DOWEL EXTENDING THROUGH SAID APERTURE AND HAVING A LOCKING COLLAR AT THE UPPER SURFACE OF SAID COVER AND DEPENDING PRONG MEANS AT THE LOWER SURFACE OF SAID COVER, SAID COLLAR AND SAID PRONG MEANS GRIPPING SAID COVER THEREBETWEEN TO SECURE SAID DOWEL TO SAID CUP, AND A FRUSTO-CONICAL LIFT MEMBER CONFORMING TO THE SHAPE OF THE INNER WALLS OF THE CUP, SECURED IN SAID CUP TO THE PRONG MEANS, AND ADHERED TO SAID INNER WALLS, THE SLANT HEIGHT OF THE LIFT MEMBER BEING GREATER THAN THAT OF THE CUP IN ORDER TO PROVIDE A FRUSTO-CONICAL PROJECTION OF THE LIFT MEMBER BELOW THE CUP. 